Root:shoot ratio of field crops under conventional and conservation tillage: A meta analysis

Abstract Conventional tillage (CT) is a widely used agricultural practice aimed at loosening soil to enhance water infiltration and root growth. However, it can lead to environmental issues such as increased soil erosion and loss of nutrients and carbon. To address these challenges, non‐conventional tillage systems like no‐tillage and minimum tillage (collectively referred to as NT) have gained popularity in recent decades. This review examines the effects of CT and NT on the root: shoot ratio (R:S) based on 28 studies covering common crops across various climates and managements. Most studies were primarily on maize, wheat, rapeseed and barley. Meta‐analysis showed non‐significant differences ( p = .27) among these crops with respect to their response of R:S to the two tillage practices. Rapeseed and barley exhibited higher R:S in NT by 2% and 15%, while maize and wheat demonstrated higher R:S in CT by 2% and 6%, respectively, although the effects where not significant. In terms of soil texture classes, crops grown in sandy soils had a higher R:S under CT than NT, but no significant differences were found ( p = .19). However, significant differences emerged among soil textures, with silty clay, sandy loam and clay loam showing the highest R:S ( p 30 cm) and shallow (<30 cm) root sampling depths. The findings indicate that more field experiments are needed to fully understand the impact of tillage methods on R:S across genotypes, environments and managements.